A hongi is a traditional Māori greeting in which one person presses their nose and forehead (at the same time) to another person. Here, soldiers participate in a welcoming ceremony at a joint military exercise between New Zealand and U.S. troops.Photograph by New Zealand Defense Force, courtesy Wikimedia. CC-BY-2.0

Discussion Ideas

New research has found some links between the shape of our noses and our geographic ancestry. What does your nose do?

Your nose helps you smell and taste (yes, taste!), but those aren’t its main functions.

Your nose is an important part of your respiratory system. It warms, cleans, and humidifies the air you breathe.

How did scientists conduct their study of nose shape?

Scientists studied 3D scans of the faces of 2,500 people from distinct climate zones around the world.

What climate areas did researchers investigate and compare? Take a look at the study map above, and compare it with today’s simple MapMaker Interactive map of the the same areas overlaid with our climate zones map layer.

Scientists looked at noses from people representing four major climate areas:

West Africa

East Asia

Northern Europe

South Asia

What differences in the seven characteristics of noses did the researchers find between the geographic regions?

Not much, actually. They found statistically significant differences in just one feature: nostril width. Generally, people whose ancestors came from warm, humid climates (West Africa and South Asia) tended to have wider nostrils, whereas people with ancestors from cold, dry climates (Northern Europe, East Asia) tended to have narrower ones.

How might different nostril width benefit different populations?

Different nostril shapes may help people breathe easy.From Smithsonian: “In the warm, humid climates … a wide nose would allow more air to be inhaled with less effort … [While in a colder, drier climate, a] more narrow nose will cause more ‘turbulence’ as air is inhaled, mixing the air together inside the nostrils to help warm it like a convection oven.”

Sex. “‘If anything has been shaped by sexual selection, it’s the face,’ says one expert. Humans use faces to evaluate a wide range of factors about their potential mates, and nose shape certainly plays into that. Consider the fact that nearly 250,000 Americans underwent rhinoplasty—commonly known as a nose job—in 2011, most of those for cosmetic reasons.” In other words, looks matter.

Human populations are much more mobile and likely to marry and have children with people from different geographic backgrounds. How might this influence the shape of our noses?

“Evolution takes a long time,” says one scientist. “If nose shape has evolved in the past to adapt to local climate, it likely took tens of thousands of years. So, my great-great-great grandkids are likely still going to have wider noses—I’m Pakistani—even if they continue to live in a colder climate, as long as they continue to marry other South Asians.”

Does this research support the idea that genetic variation can largely be attributed to differences among people from different continents?